Century’s End Awakening

The developers describe how their game uses AI generated content like this:

Official AI Usage Statement: Some of the soundtracks in the game have been procured from commercial music large-scale models and are accompanied by commercial licensing certificates. The initial rough models of certain game elements were generated by commercially viable large-scale models to assist in the development process.

Required on Steam store pages since 2024. It covers content that ships in the game, on its store page or in its marketing — Valve does not require a disclosure for AI tools used during development, so this says nothing either way about how the game was made. Check it on Steam.